“THE people’s police love the people, the people love the people’s police” is a well-known ditty that officials claim is cherished and accurate. Earlier this month, however, Global Times, a newspaper in Beijing, said that police were struggling to convince the public that they had acted properly in the case of a 29-year-old man who died in the capital while in their custody. Disdain for and distrust of the police is, in fact, widespread. But it is rare for an organ so closely linked to the Communist Party to admit that officers have a credibility problem.

Police said they had detained the man, Lei Yang, on May 7th during a raid on a brothel; that he had resisted arrest and died of a heart attack. His family and friends used social media to challenge this account. They said that Mr Lei was fit and had no record of heart trouble; that he was on his way to the airport to pick up relatives when he disappeared; and that timings and other details given by the police were implausible. These counterclaims created a firestorm online, and even in state-linked media.

In sci-fi movies, space habitats are huge structures with labyrinth layouts. But Hollywood doesn’t have to deal with the issues real aerospace engineers face when contemplating future space homes — such as gravity and financial constraints.